Gaskets

ABSTRACT

A gasket insertable in a pipe joint has a toroidal body with three circular grooves of concave profile centered on the body axis and separated by broad annular ribs of convex profile curved about its centerline.

United States Patent Lansaque et al.

, [s41 GASKETS [72] Inventors: Rene Lansaque, Meyzieu, Rhone; GeorgesBonnefond, Tassin-la Demi- Lune, Rhone, both of France [73] Assignee:Societe Chimique De Gerland, Lyon, Rhone, France V [22] Filed: Oct. 27,1970 [21] Appl. No.: 84,314

[52] [1.8. CI. ..277/207, 277/DlG. 2, 285/DIG. 9 [51] Int. Cl. ..Fl6j15/10 [58] Field of Seareh....277/207, 207 A; 285/DIG. 19, 285/230, 231,240, 245; 25 l/DlG. 1

[15] 3,690,684 1 Sept. 12,1972

[56] References Cit-ed FOREIGN PATENTS 0R APPLICATIONS 6,410,255 3/1965Netherlands ..277/207 A Primary Examiner-William F. ODea AssistantExaminer-Robert l. Smith Attorney-Karl F. Ross s7 ABSTRACT A gasketinsertable in a pipe joint has a toroidal body with three circulargrooves of concave profile centered on the body axis and separated bybroad annular ribs of convex profile curved about its centerline.

2 Claims, 2 Drawing; Figures Patented Sept. 12, 1972 VENTORS NN'EFONDRen LANS Georges BO 9 ml, 10S;

a 1 GASKETS The present invention relates to an annular sealing gasketfor tubes and pipes, and more particularly for joints betweenlarge-diameter tubes and pipes, such for example as those in main sewersand other drainage pipes.

The. necessary fluidtightness at the junction of two such pipes isgenerally effected by rubber gaskets. At prese'nt,the gasket mostgenerally used is an O-ring which is inexpensive and guarentees a tightjoint. Nevertheless, such a ring does have disadvantages, particularlyin the case where the male part of the pipe junction is more or lesstapered. Indeed, in this case, the gasket tends to roll on the male pipeend to a position in which it is no longer pressed bythat pipe againstthe female coupling flange surrounding same.

Moreover, this type of gasket does not ensure the relativeimmobilization of the pipes after their assembly. On the contrary, itoften exerts an undesirable reverse force upon the pipe which has justbeen put into position.

In addition, at the time of mounting, the annular gasket, onaccount ofits shape, does not assist the mutual alignment or interfltting of thetwo pipes since it slips under the thrust of the female pipe and thusprovides no positive guidance.

Various other types of gaskets have been produced in order to remedythese disadvantages. However, these devices have never been able tocombine, at one and the same time, reliable positioning of the gasket onthe pipe body without rolling or escaping, relative immobilization ofthe pipes in the assembled position without yielding of one of them,easy alignment of the pipes, and good air-tightness.

This is why certain gaskets, in order to ensure simultaneously theimmobilization of the pipes in the mounted position and goodfluidtightness, comprise regions of extra thickness. Therefore, duringmounting, it is necessary to exert considerable force in order toassemble the-pipes, at the risk of causing rupture of the couplingflange. e

In addition, the resulting excessive compression of the gasket may leadto a very early deterioration of the latter and to damage of the pipeflange within a fairly short period.

Moreover, taking into account the considerable weight of the pipesgenerally used, the deformation of these gaskets is very different intheir upper and lower parts.

. Thus, it is an object of the present invention to remedy thesedisadvantages, and for this purpose, according to the invention, weprovide an annular gasket of flexible material where surface is formedwith three coaxial circular grooves (e.g., an inner groove and two outergrooves) spaced 120 apart about the circular centerline of the gasketbody.

Our improved gasket substantially retains the qualities of theconventional annular gasket O-ring, but does not have its disadvantages,by virtue of the presence of these three grooves, one of which alwaysstraddles the inner or male pipe termination or the surrounding flangeor female termination and thus gives the gasket a firm seating on thepipe body, ensures relative immobilization of the assembled pipes, asubstantially uniform compression of the gasket over all its parts, anda tight joint.

According to a preferred embodiment of the invention, the circulargrooves have a profile of concave shape, facilitating the relativealignment of the pipes.

At the time of interengagement of the two pipes, the gasket is placed onthe terminal portion of one of the pipes with one of its concave groovesconfronting the peripheral surface of that pipe while another of itsgrooves faces the front edge of the second pipe which, during theassembly, is received in the latter groove, thus ensuring a properrolling of the gasket about its centerline and the correct coaxialpositioning of the two pipes.

An embodiment of the present invention will now be discribed, by way ofexample, with reference to the accompanying drawing in which:

FIG. 1 is a cross-sectional view, on a diametrical plane, of an annulargasketaccording to the invention; and

FIG. 2 is a cross-sectional view, on a diametrical plane, showing theassembly of two pipes with interposition of the gasket.

F IG. 1 shows a gasket 2 according to the present invention. This gaskethas an annular body of toroidal shape in which there have been out threecircular grooves 2a,-2b, and 2c, centered on the body axis, whosecross-section is in the form of a segment of a circle. Thesegrooves 2a,2b, 2c'are spread apart about the centerline of the gasket body anddefine between them three broad support surfaces 3a, 3b and- 3c in theform of annular ribs of convex profile (curved about the centerline)spanning arcs somewhat smaller than those of the groove segments.

The assembly of this gasket 2 and with the pipes 4 and 5 into afluidtight joint takes place in the following manner:

The gasket is fitted'around the male termination of the joint,i.e.,thefront end 5a of the pipe 5, and is positioned in such a way that one ofits grooves, here the inner groove 2a, confronts the outer surface ofthe pipe end 5a, as shown in the drawing.

The female end of pipe 4 is then moved toward the pipe 5 with thefrontedge 4b of the flange 4a thereof entering the groove 2b whose concaveshape ensures, as will be seen, a correct adjustment of the pipes 4 and5.

As will also be seen, the gasket 2 cannot slip during the interfittingmotion, on account of its seating on the pipe end 5a at this instant,and consequently rolls over under thrust of the edge 4b of flange 4a.

As the gasket 2 rolls on the pipe end 5a, it is always in contact withthe outer surface of pipe 5 and with the inner surface of the flange 4aby at least two of its support surfaces 3a, 3b, Be as the successiveposition of the gasket shown in broken lines in FIG. 2 indicate.

In its final position, illustrated in continuous lines in FIG. 2, thegasket 2 is locked and ensures the relative immobilization of the pipes4 and 5 without any risk of a backward movement of the pipe last put inplace. Such a self-locking of the gasket occurs, during its rollingmotion, once every 120, i.e., a possible separating movement of the twopipes would in the most unfavorable case be limited to an arc length ofabout 60 of the gasket cross-section.

Moreover, this gasket 2 has a resistance to crushing which is comparableto that of a conventional annular gasket, that is to say, itscompression is virtuallyuniform over its entire length, whatever itsangular position.

We claim:

1. A sealing gasket for a pipe joint, comprising a toroidal body offlexible material formed with three circular grooves centered on theaxis of said body and paralleling the centerline thereof, said groovesbeing angularly equispaced about said centerline and being ceeding thosespanned by the cross-sections of said ribs.

1. A sealing gasket for a pipe joint, comprising a toroidal body of flexible material formed with three circular grooves centered on the axis of said body and paralleling the centerline thereof, said grooves being angularly equispaced about said centerline and being separated by broad annular ribs of convex cross-section curved about said centerline.
 2. A gasket as defined in claim 1 wherein said grooves are concave in cross-section and span arcs exceeding those spanned by the cross-sections of said ribs. 